The present invention relates generally to crop harvesting machines, commonly referred to as combines, and, more particularly, to providing a header attachment mechanism which will give flexibility to adjusting the position of the header relative to the ground.
Combines, particularly the self-propelled type, are equipped to utilize a variety of crop gathering headers, including headers specifically designed for harvesting corn, cereal grains or soy beans. Normally, these headers are attached to the forward end of the feeder house, which is a structure used to convey crop material from the header to the combine base unit for further harvesting treatment. As is shown in U.S. Pat. No. Re. 26,512, the forward end of the feeder house can be constructed so that the header can be quickly and easily attached thereto. Usually, the feeder house structure is rectangular in shape and includes a rectangular crop inlet opening at the forward end.
Providing the capability for a combine header to both rotate laterally, to follow the contour of the ground, and to rotate in a fore-and-aft direction, to adjust the cutting angle of the header cutting means relative to the ground, has become increasingly desirable. As can be seen in U.S. Pat. No. 3,981,125, U.S. Pat. No. 3,731,470, U.S. Pat. No. 3,638,407 and U.S. Pat. No. 3,474,606, various structures have been developed to provide either one function or the other. Problems with the prior art structures include increased crop losses occurring with header adjustments, increased wear and short life of the feeder house components and feeding problems with the crop conveying means within the feeder house.
Changing the cutting angle of the header cutting means relative to the ground is particularly important for the harvest of soy beans, as the grain portion of this crop lies closer to the ground than for other crops. Furthermore, since changing tire sizes on the combine causes changes in the aforementioned cutting angle, it is of further importance to provide such a capability to correct such cutting angle changes. Since it has been found that an increase in the distance between the header and the crop conveying means will detrimentally affect the efficiency of the feeder house crop conveying means to engage crop material to feed it rearwardly, it is particularly advantageous to provide the capability of adjusting the cutting angle without increasing this header to crop conveying means distance.
Lateral flotation of the header has an increasingly greater importance with the increasing sizes of crop gathering headers because the larger headers are more susceptible to changes in the ground contour in that a ground contour change could result in one end of the header being above the crop material with no crop being harvested. To provide the header with the capability to float, and thereby follow the ground contour, enables the header to gather more crop material and reduce losses. Twisting the feeder house to laterally move the header creates many of the aforementioned problems which the present invention attempts to avoid.